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Heat pumps · IE

ViessmannIDU-A Hybrid HWMIW.A1.19-V054 / ODU 250-A AWMOF-251.A1.13-400-V002

The Viessmann IDU-A Hybrid HWMIW.A1.19-V054 / ODU 250-A AWMOF-251.A1.13-400-V002 is an air-to-water heat pump with a SCOP of 5.09 (35 °C) and a sound power level of 50 dB(A). In Ireland a heat pump is exempt from planning permission if it stays below 43 dB(A) (or 5 dB(A) above background noise, if higher), measured at the nearest neighbouring inhabited dwelling. Free-standing, the indicative minimum distance is 0.9 m; against a wall 1.3 m.1

Last updated: Technical specifications Rules in Ireland ⇄ Compare this model
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SCOP (35 °C)
5.091

Seasonal efficiency: how much heat you get per kWh of electricity across a heating season.

Heating capacity (A7/W35)
8.14kW1
Official source
Outdoor unit sound power
50dB(A)1
Official source
Refrigerant
R2901
Official source
Type (source)
Air-to-water1
Official source
IE

Rules in Ireland

These rules are still being verified.

Minimum distance to your neighbour

Planning and Development Regulations 2001 (S.I. No. 600/2001), Sch. 2, Part 1, Class 2(d), inserted by S.I. No. 83/2007; location rules relaxed by exempted-development regulations of July 2026 (incl. S.I. No. 342/2026)2 · nearest neighbouring inhabited dwelling

Planning exemption: max 43 dB(A), or 5 dB(A) above background noise if higher ≤ 43 dB(A) · normal operation
Free-standing 0.9 m
Against wall 1.3 m
In corner 1.8 m

Indicative calculation (hemispherical, no barriers). Your installer must confirm the noise level at the nearest neighbouring dwelling.

SEAI Heat Pump System Grant

Not eligible

Up to €14,500 for a house (€11,500 for an apartment), including a €2,000 boiler scrappage grant when an oil, gas, solid-fuel or storage-heater system is removed. Homes built before 2007 need a technical assessment (€200 grant) unless the BER shows a Heat Loss Indicator of 2.3 or less. Installation is charged at 9% VAT.4

  • The heat pump must be listed on SEAI's Home Appliance Register of Performance (HARP) and installed by an SEAI-registered contractor.
  • Home built and occupied before 2021, with an MPRN; grant approval before any work starts and a BER assessment afterwards.
  • Hybrid heat pumps (with a gas or oil boiler) are not covered by the SEAI heat pump grant.

Technical specifications

General
Type (source) Air-to-water1
System Hybrid (with gas boiler)1
Performance
Heating capacity (A7/W35) 8.14 kW1
Rated output 35 °C 12.42 kW1
Rated output 55 °C 12.1 kW1
Min. outdoor temperature -20 °C1
Efficiency
SCOP (35 °C) 5.091
SCOP (55 °C) 4.131
Seasonal efficiency ηs 35 °C 200.8 %1
Seasonal efficiency ηs 55 °C 162 %1
Energy label 35 °C A, , , 1
Energy label 55 °C A, , , 1
COP A7/W35 5.391
Noise
Outdoor unit sound power 50 dB(A)1
Indoor unit sound power 40 dB(A)1
Refrigerant
Refrigerant R2901
Refrigerant GWP 31
Refrigerant charge 2 kg1

Manufacturer documentation

External links to Viessmann's official website. The manufacturer may change or move documents; where they differ, the manufacturer's latest version applies.

Frequently asked questions

Do I need planning permission for the Viessmann IDU-A Hybrid HWMIW.A1.19-V054 / ODU 250-A AWMOF-251.A1.13-400-V002 in Ireland?

Not if it meets the exempted-development conditions (Planning and Development Regulations 2001 (S.I. No. 600/2001), Sch. 2, Part 1, Class 2(d), inserted by S.I. No. 83/2007; location rules relaxed by exempted-development regulations of July 2026 (incl. S.I. No. 342/2026)): no more than 43 dB(A) at the nearest neighbouring inhabited dwelling, or 5 dB(A) above background noise if that is higher. With a sound power of 50 dB(A) that indicatively means 0.9 m free-standing, 1.3 m against a wall or 1.8 m in a corner. Ask your SEAI-registered installer to confirm.1

Which refrigerant does the Viessmann IDU-A Hybrid HWMIW.A1.19-V054 / ODU 250-A AWMOF-251.A1.13-400-V002 use?

The Viessmann IDU-A Hybrid HWMIW.A1.19-V054 / ODU 250-A AWMOF-251.A1.13-400-V002 uses R290.1

Sources

  1. Heat Pump Keymark certificates — EHPA / DIN CERTCO (Heat Pump KEYMARK) · accessed 29 Sept 2026
  2. Planning and Development Regulations 2001 (S.I. No. 600/2001), Sch. 2, Part 1, Class 2(d), inserted by S.I. No. 83/2007; location rules relaxed by exempted-development regulations of July 2026 (incl. S.I. No. 342/2026)
  3. Heat Pump System Grants — SEAI · accessed 4 Oct 2026
  4. Heat pump heating system (VAT) — Revenue · accessed 4 Oct 2026